To grasp the significance of Donald Trump’s decision to replace Rex Tillerson with Mike Pompeo, it’s worth remembering how Tillerson became secretary of state in the first place. He got the job, in large measure, because Condoleezza Rice and Robert Gates urged Trump to hire him. Rice and Gates knew Tillerson because they both consulted for his company, Exxon, and because Tillerson sat alongside Gates on the board of the Boy Scouts. In explaining the logic behind pushing for Tillerson, Rice toldThe New Yorker’s Dexter Filkins that, “This president doesn’t trust the foreign-policy establishment. A businessman who has made big oil deals—we thought that would be something that Trump would be comfortable with.”

Tillerson, in other words, was a Trojan horse. Rice and Gates figured that Trump would focus on the externals. He’d see Tillerson as a deal-making, alpha male, rich guy like himself. They may also have suspected what some Trump advisers later confirmed: That Trump thought Tillerson looked like a secretary of state.

But Rice and Gates knew that, under the surface, Tillerson shared their worldview. From his time at Exxon, he had learned to put ideology aside and manage relationships with governments as diverse as Russia’s, Mexico’s, and Qatar’s. He had participated in a business group that generally opposed the economic sanctions that impeded U.S. corporations, including against Iran. Under his leadership, Exxon had acknowledged that human activity was contributing to climate change and endorsed the Paris climate change accord. During the primaries, Tillerson had contributed to Jeb Bush.

Like Rice and Gates, Tillerson was—in Walter Russell Mead’s terminology—a “Hamiltonian.” He believed in prudently managing America’s empire so that American business, and by extension the American people, could prosper. He was not a crusader, a risk-taker, or a moralist. And he didn’t see America’s relationships with other powerful nations as zero-sum. In Tillerson, Rice and Gates saw a chance to smuggle into the Trump administration the moderate Republican foreign-policy establishment that they had served for much of their lives.

That establishment dates back to the era of Elihu Root and Henry Stimson, patrician lawyers who, at the dawn of America’s global power in the late 19th and early 20th century, journeyed back and forth between government and Wall Street. Like their patron, Theodore Roosevelt, they were imperialists. Root backed the Spanish-American War. A quarter-century later, Stimson argued that the Philippines, which the U.S. had occupied as a result of that war, still didn’t deserve independence. But Root and Stimson also believed that to fulfill its global destiny, the United States should make binding international commitments and join international institutions. Bucking many in their party, both men supported America’s entrance into the League of Nations, the failed precursor to the UN. On domestic issues, both were moderates. They believed that a certain dose of progressive reform could help preserve domestic stability. Root supported the creation of a federal income tax. Stimson crossed party lines—and to some betrayed his class—by in 1940 becoming Franklin Roosevelt’s Secretary of War.

Yet another, more right-wing, strain of foreign policy thinking also enjoyed influence in the GOP. In the 1930s, its devotees were mostly isolationists. But during the Cold War, many recast themselves as hawkish unilateralists. Throughout that period, right-wing politicians and activists attacked Root and Stimson’s heirs for being too willing to sacrifice America’s sovereignty, accommodate America’s enemies, and tolerate the welfare state.

In the 1950s, Root and Stimson’s legacy was carried on by Dwight Eisenhower and John Foster Dulles, his corporate lawyer turned secretary of state. They conceded that America would have to contain—not rollback—Soviet power. And they accepted a draw in the Korean War. This put them at odds with right-wingers like Douglas MacArthur, who wanted to fight until the Korean Peninsula was reunified; Joseph McCarthy, who believed America could win the Cold War by ferreting out communists at home; and Robert Taft, who considered nato a dangerous infringement on America’s sovereignty. The American right, while determined to vanquish communism, was skeptical of binding commitments that obligated America to manage a messy, imperfect world.

By the 1960s, these right-wing instincts had congealed into the modern conservative movement. Its champion, Barry Goldwater, called for liberating Eastern Europe, leaving the United Nations if it admitted Communist China, and making it easier for American officers in the field to use nuclear weapons. But while Goldwater beat his moderate establishment challenger, Nelson Rockefeller, for the 1964 GOP nomination, it was Richard Nixon, Eisenhower’s old vice president, who in 1968 returned the presidency to Republican hands. Nixon had been Class-A red-baiter. But in office, he and his top foreign-policy aide, Henry Kissinger, treated the Cold War less like a crusade than a chess match. And by opening diplomacy with China, and pursuing détente with the Soviet Union, they incurred the conservative movement’s wrath.

In 1980, that movement finally elected a president. But to its immense frustration, Ronald Reagan chose the establishment-minded James Baker—who had run Gerald Ford and George H.W. Bush’s primary campaigns against him in 1976 and 1980—as his chief of staff. And he chose as his secretary of state George Schultz, who as Nixon’s secretary of labor had overseen the first affirmative action plan. Through them, the moderate Republican foreign-policy establishment endured. Schultz, in particular, helped convince Reagan to embrace the Soviet leader Mikhail Gorbachev and—while conservative politicians and pundits screamed appeasement—to negotiate the most far-reaching arms control agreement of the Cold War.

Under George H.W. Bush—who made Baker his secretary of state, and made Brent Scowcroft, Kissinger’s one-time assistant, his national-security adviser—the Republican foreign-policy establishment reached its zenith. Then, under George W. Bush, it collapsed.

W.’s first National Security Advisor, Condoleezza Rice, was a Scowcroft protégé. His first secretary of state, Colin Powell, was a classic Rockefeller Republican. But they couldn’t or wouldn’t halt his and Dick Cheney’s march to war. In part, that’s because by the George W. Bush years, the moderate Republican foreign-policy establishment no longer had a political base inside the GOP. The conservative movement had taken over the party. And its organs—think tanks like the Heritage Foundation and American Enterprise Institute, publications like The Weekly Standard and networks like Fox News—overwhelmingly backed the war. By the early 21st century, arguing inside the GOP for a foreign policy based on diplomacy, containment, and the embrace of international institutions was about as popular as arguing for higher taxes or gun control.

When Barack Obama expressed his admiration for Scowcroft, won the endorsement of Colin Powell, and hired Robert Gates, many took it as evidence that the Hamiltonian approach epitomized by Republicans like Stimson, Eisenhower, Nixon, and George H.W. Bush now fit more comfortably inside the Democratic Party. The moderate Republican foreign-policy establishment was no longer Republican at all.

Tillerson was a pathetic last gasp. He argued against tearing up the Iran nuclear deal, tried to pursue diplomacy with North Korea, and opposed pulling out of the Paris climate accord. But these views simply alienated him from Trump, who sees any deal he has not brokered as a rip-off. And in a bitter irony, Tillerson—despite believing in diplomacy—emasculated the State Department, thus undermining America’s capacity to pursue it for years to come.

In Pompeo, Trump is turning to a new Republican foreign-policy elite: one whose ideological lineage dates not to Eisenhower but to McCarthy, not to Nixon and Kissinger but to Goldwater, not to George H.W Bush but to Dick Cheney and George W. Bush. The conservative movement, long hostile to its party’s moderate foreign policy establishment, is creating a new foreign policy establishment of its own.

It’s useful to see Pompeo as part of a cadre of influential, foreign policy-oriented, Republican politicians that includes Tom Cotton, Marco Rubio, and Ted Cruz. All four were elected to Congress with support from the Tea Party, a movement that depicted moderate Republicans —as Goldwater once depicted Eisenhower and Nixon—as complicit with the welfare state. Pompeo has particularly close ties to the Tea Party’s most important funders, the Koch Brothers.

On foreign policy, the American right has historically oscillated between isolationism and crusading interventionism. The Koch Brothers and Rand Paul lean toward isolationism. Rubio and Cotton lean toward crusading interventionism. What they all share is self-righteousness. The United States is pure; its adversaries are wicked. Thus, America must either shun other nations or dominate them. What it cannot do is recognize that even its adversaries have reasonable fears and legitimate interests, which America should try to accommodate.

Because America is pure and its enemies are evil, accommodating them is immoral. Like Goldwater and William F. Buckley, who saw compromise with communist regimes as appeasement, Pompeo has called the Iran deal “surrender” and insisted that the United States make “no concessions” in any talks with North Korea.

By depicting accommodation as surrender, the Cold War right opened the door to preventive war. James Burnham, perhaps the most influential foreign policy writer at Buckley’s magazine, National Review, all but proposed a preventive war to prevent the Soviet Union from attaining nuclear weapons. Buckley proposed using nuclear weapons to stave off defeat in Vietnam. Similarly, Pompeo—like Cotton—has said destroying Iran’s nuclear program via war is “not an insurmountable task.” And unlike Tillerson, he has described America’s goal in North Korea as regime change.

Historically, the right’s belief in America’s purity—and the impurity of other nations—has also made it skeptical of binding the United States to international institutions or within international law. Tillerson acknowledged that America was contributing to climate change, and should participate in global agreements aimed at mitigating it. Pompeo disagrees.

This same insistence on America’s moral purity has informed Pompeo’s fervent refusal to acknowledge that the United States committed torture. In 2014, when the Senate Intelligence Committee released part of a 6,000-page report exposing that the CIA had brutalized detainees—and repeatedly lied about it—Pompeo insisted that, “These men and women are not torturers, they are patriots” working to “crush the Islamic jihad that threatens every Kansan and every American.” The statement—reminiscent of Goldwater’s famous declaration that “Extremism in defense of pursuit of liberty is no vice”—was essentially a declaration of American impunity. Because, by definition, America’s cause is just, anything America does to achieve it is just too.

A final aspect of the right-wing foreign policy tradition is its penchant for finding enemies at home. If you see compromise as surrender, and America’s enemies as demonically powerful, it stands to reason that behind America’s policies of appeasement lies a domestic fifth column. This was Joseph McCarthy’s explanation for the Roosevelt, Truman, and Eisenhower administration’s willingness to allow communist domination of Eastern Europe, a communist victory in China, a stalemate in Korea, and the USSR’s development of an atomic bomb. Why had American presidents permitted these calamities? Because, McCarthy argued, communists had infiltrated the United States government itself.

When it comes to Muslims and Islam, Pompeo is McCarthy’s heir. Like his allies Frank Gaffney and Brigitte Gabriel, he has suggested that America’s most prominent Muslim organizations are fronts for the Muslim Brotherhood, which he claims is plotting to overthrow the United States government from within. In one appearance on Gaffney’s radio show (Pompeo has appeared over 20 times), he asserted that, “There are organizations and networks here in the United States tied to radical Islam in deep and fundamental ways. They’re not just in places like Libya and Syria and Iraq, but in places like Coldwater, Kansas, and small towns all throughout America.” And, like Gaffney, Pompeo has claimed these networks had sympathizers inside the Obama administration. In a 2015 interview, Gaffney suggested that Obama has “kind of an affinity for, if not the violent beheading and crucifixions and slaying of Christians and all that, but at least for the cause for which these guys are engaged in such activities.” Pompeo’s reply: “Frank, every place you stare at the president’s policies and statements, you see what you just described.”

For several years, Gaffney and Gabriel—in partnership with Ted Cruz—have pushed to designate the Muslim Brotherhood as a terrorist organization, which could pave the way for legal attacks on prominent American Muslim organizations as abettors of terrorism. As Secretary of State, Tillerson opposed that. In Congress, Pompeo supported it. If such a designation occurs, it will be the closest post-9/11 equivalent to the 1954 Communist Control Act, which criminalized membership in the Communist Party. Except that it will target Americans not based merely on their ideological affiliation but on their religion as well.

Pompeo’s elevation represents a historical breakthrough. Never in American history has a secretary of state so firmly espoused the worldview of the American right. In no previous Republican administration—not even George W. Bush’s—has the moderate GOP foreign policy elite lost its hold over even Foggy Bottom.

They may never get it back. If Tillerson’s departure heralds the demise of one Republican foreign-policy establishment, Pompeo’s ascension may herald the rise of another. Pompeo’s legitimacy does not only derive from the job he will now hold. It also derives from his credentials. Like Cotton, Pompeo had a distinguished military career. Like Cotton and Cruz, he graduated from Harvard. While his worldview overlaps heavily with those of Steve Bannon, Sebastian Gorka, and Mike Flynn, Pompeo enjoys a prestige they never did. His rise offers a glimpse into a Trumpism that can outlast Trump, and gives new respectability to a strain of foreign-policy thinking that has generally lacked it in the past.

Rex Tillerson was one of the least consequential secretaries of state in modern American history. Mike Pompeo, for better or worse, may prove to be one of the most.